from PyQt5 import QtWidgets

if __name__=='__main__':
    app=QtWidgets.QApplication([])    # 必须要有App的初始化,不然没法启动
    w = QtWidgets.QWidget()
    w.resize(250, 150)
    w.move(300, 300)
    w.setWindowTitle('Simple')
    w.show()